1. Field of the Invention
The present invention relates to an input device, a control method of the input device, and a program, and particularly to an input device, a control method of the input device, and a program that for example enable a higher-level application or the like to use height information on height from a display screen of an external input performed by bringing an object close to the display screen.
2. Description of the Related Art
As a panel that can output information on a plurality of points on the panel, for example, a display panel has been proposed which includes an optical sensor in a liquid crystal display device and detects input of external light by the optical sensor, thereby enabling input by light (the display panel will hereinafter be referred to as an input-output panel) (see Japanese Patent Laid-Open No. 2000-019478 and Japanese Patent Laid-Open No. 2004-127272).
Methods of performing input by light on an input-output panel are roughly divided into methods using light incident on a liquid crystal display device from an external light source such as an LED (Light Emitting Diode) or the like as a result of a user bringing an object (such as a pen) having the external light source close to the display screen of the liquid crystal display device and methods using light emitted by a liquid crystal display device, that is, the transmitted light of the backlight of the liquid crystal display device which light is reflected by an object such as a finger, a pen or the like without such an external light source which object is coming close to the display screen, and then returned to the inside of the liquid crystal display device as a result of a user bringing the object close to the display screen.
In addition, a touch panel of a pressure-sensitive type or the like outputs point information as information on a point on the touch panel (which information is for example the coordinates of the point) at which point an external input is performed. However, the point information can be output for only one point.
Specifically, for example, even when a user brings fingers or the like close to two points on the touch panel, the touch panel outputs point information on only one of the two points to which point a stronger pressure is applied or which point is touched first, for example.
On the other hand, the input-output panel can output point information on a plurality of points, and is thus expected to be applied in the future to products and the like to which the touch panel of the related art has been applied.